Roger "Buzz" Osborne, also known as King Buzzo (born March 25, 1964) is the American guitarist/vocalist/songwriter and technically the only remaining founding member of the Melvins (drummer Dale Crover is often regarded as a founding member, but he joined after the band was formed, though before they had yet recorded an album). He's also collaborated with various other artists such as Cows and Tool. Osborne is additionally a founding member/guitarist for both the groups Fantômas and Venomous Concept. He was a high school friend of Kurt Cobain and the bassist for Cobain's first band, Fecal Matter.

In 1988, Osborne, with Crover, relocated to San Francisco where the band recorded their next album, Ozma, in May 1989. It was released later that year.

Osborne, along with the rest of the Melvins, knew the members of Nirvana. When Dave Grohl's first band, Scream, disbanded, he approached Osborne for advice. Osborne, in response, introduced Grohl to Kurt Cobain and Krist Novoselic. The influence of the Melvins can be clearly felt on Nirvana's music, especially their early, Bleach-era work.

In 1997, Osborne appeared in the promo video for The Offspring's video "All I Want," as a masked pianist. Osborne also appears in the 1994 video for the Beck song "Beercan" which samples the Melvins' song "Hogleg."

Buzz joined Tool onstage during their tour for Ænema. The Melvins also opened for Tool on the tour. In 1998, Osborne joined a new band known as Fantômas with Faith No More vocalist Mike Patton, a band which he remains involved with to the present day.

Osborne has remarked, "From a very early age I was interested in underground music. I never appreciated the big stadium shows in the first place— I cut my milk teeth musically on smaller shows. A much more intimate basis. That’s the lessons I learned from punk rock that I never forgot. That extends to today." As referred to before, he had a very wide set of musical influences since his childhood, ranging from arena rock to glam rock to punk to power pop and more. Osborne has called himself a lifelong "musical anthropologist" and stated that "since I never grew up around people who gave me any indication of how one was supposed to act, I was equally excited seeing the Kinks as I would be by seeing a punk rock band. Or Cheap Trick." In terms of hip hop music, he's stated that his favorite rap album is Run-D.M.C.'s Raising Hell.[3]

Though having a diverse range of styles played by his band, the Melvins have been referred to as being like 'Godfathers' of the grunge movement.[4]

In a 2011 interview with the music magazineL.A. Record, Osborne stated when asked about American politics that "I hate conservatives, but I really hate liberals. Here's the thing. I have my own opinions about everything, and it's basically classic liberalism."[3] In 2008, he told the magazine Alarm that he opposes what he sees as both modern socialist and fascist thought, stating that he's "into true liberalism, which means you mind your own goddamn business; you take care of yourself."[4] In a 2014 interview with Tonedeaf, Osborne expressed that American economist, Thomas Sowell, has been a major influence on his career. "I consider Sowell the greatest philosopher of all time." Osborne explained. "He is a PhD economist and he's written more than 30 books about everything you can imagine, from social commentary to how economics works."

In terms of issues covering copyright and illegal file-sharing of songs (such as in the warez scene), Osborne's remarked, "The internet downloading— people need to get over it". He's also added, "Is it stealing? Sure, yeah— but it doesn't matter. It's over. Things have changed. We have to move on."[4] In an earlier interview, he argued, "For me musically, I wish I woulda had something like YouTube when I was a kid so I could go, 'Oh, what’s this Captain Beefheart?'"[3]